The present invention relates to temperature control systems and, more particularly, to a multi-stage commercial refrigeration system.
Glycol-based fluids are commonly employed as coolant fluids. The formulations used are typically based on alkylene glycols such as ethylene and propylene glycol. However, problems exist with the use of these compounds as coolant fluids in certain applications. One use of such compounds is in commercial refrigeration systems. At temperatures approaching xe2x88x9240xc2x0 F., the viscosity of propylene glycol compounds increases to the point where their use becomes impractical in commercial refrigeration systems charged with maintaining very low temperatures in product zones of the refrigeration units. This causes high pressure drop, low mechanical efficiency and high power consumption in the refrigeration system. In addition, ethylene glycol compounds are toxic. This causes concerns with regard to piping system integrity and problems with regard to detecting, repairing and cleaning up system leaks, changing of the refrigerant and disposal of the used refrigerant.
In view of the above, a requirement exists for a non-toxic heat transfer fluid having a viscosity low enough at temperatures down to approximately xe2x88x9240xc2x0 F. to be used as a coolant fluid. A need also exists for a system which utilizes such a working fluid.